Parkinson's disease is a common, progressive degenerative neurological disease affecting people in middle age, often during their most productive years. The resulting long term disability causes a large economic burden to the person, their family, and to society. While symptoms may be relieved by medications which alter dopamine neurotransmission in the nervous system, no treatment has been proven to slow the underlying progression of the degenerative process. The Movement Disorders Program of the Medical University of South Carolina proposes to participate as a clinical trial center, testing agents with potential to delay the progression of disability (and perhaps the pathological process) in Parkinson's disease. Utilizing neurologists with special expertise in movement disorders and clinical research coordinators experienced in the conduct of trials of clinical therapeutics in Parkinson's disease, we propose to perform pilot studies and comprehensive multicenter double blinded clinical trials of selected agents in Parkinson's disease patients, early in their disease and with limited exposure (if any) to therapeutic agents. Candidate agents will be selected by a National Institutes of Health-based central organization of scientists and clinicians for their potential to slow the cellular events associated with progressive parkinsonism. This center proposes to study at least 24 patients in each trial yearly over a five year period of time, recruiting volunteers from an established referral network of primary care physicians, community agencies, and neurologists in the region. Using established clinical protocols and procedures, the site will act as part of a large consortium, collaborating closely with the Neurodegeneration and Clinical Trial Group Coordination and Statistical Centers, providing a mechanism for the rapid, efficient and uniform evaluation of the potential of new agents to combat this neurological disorder.